CHANGED_COLUMNS

Using this type of locking policy compares only the changed fields
in the WHERE clause when doing an update. If any field has been
changed, an optimistic locking exception will be thrown. A delete
will only compare the primary key.

SELECTED_COLUMNS

Using this type of locking compares selected fields in the WHERE
clause when doing an update or a delete. If any field has been
changed, an optimistic locking exception will be thrown. Note that
the fields specified must be mapped and not be primary keys.

valueOf

Returns the enum constant of this type with the specified name.
The string must match exactly an identifier used to declare an
enum constant in this type. (Extraneous whitespace characters are
not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant
with the specified name